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 */
package com.semi.util;

/**
 *
 * @author liaoyq
 */
public class IPv4Util {
    private final static int INADDRSZ = 4;
    public final static int MASK_SINGLE = 0xFFFFFFFF;
    public final static int MASK_NET_C = 0xFFFFFF00;
    public static int maskToInt(int mask){
        int a = 0x80000000;
        int i;
        for( i=0;i<32;i++){
            if( (mask & a )==0 ) break;
            a = a>>>1;
        }
        return i;
    }
 /**
     * 把IP地址转化为int
     * @param ipAddr
     * @return int
     */
    public static byte[] ipToBytesByReg(String ipAddr) throws FormatException {
        byte[] ret = new byte[4];
        try {
            String[] ipArr = ipAddr.split("\\.");
            ret[0] = (byte) (Integer.parseInt(ipArr[0]) & 0xFF);
            ret[1] = (byte) (Integer.parseInt(ipArr[1]) & 0xFF);
            ret[2] = (byte) (Integer.parseInt(ipArr[2]) & 0xFF);
            ret[3] = (byte) (Integer.parseInt(ipArr[3]) & 0xFF);
            return ret;
        } catch (Exception e) {
            throw new FormatException(ipAddr + " is invalid IP");
        }

    }

    /**
     * 字节数组转化为IP
     * @param bytes
     * @return int
     */
    public static String bytesToIp(byte[] bytes) {
        return new StringBuffer().append(bytes[0] & 0xFF).append('.').append(
                bytes[1] & 0xFF).append('.').append(bytes[2] & 0xFF)
                .append('.').append(bytes[3] & 0xFF).toString();
    }

    /**
     * 根据位运算把 byte[] -> int
     * @param bytes
     * @return int
     */
    public static int bytesToInt(byte[] bytes) {
        int addr = bytes[3] & 0xFF;
        addr |= ((bytes[2] << 8) & 0xFF00);
        addr |= ((bytes[1] << 16) & 0xFF0000);
        addr |= ((bytes[0] << 24) & 0xFF000000);
        return addr;
    }

    /**
     * 把IP地址转化为int
     * @param ipAddr
     * @return int
     */
    public static int ipToInt(String ipAddr) throws FormatException {
            return bytesToInt(ipToBytesByReg(ipAddr));
    }

    /**
     * ipInt -> byte[]
     * @param ipInt
     * @return byte[]
     */
    public static byte[] intToBytes(int ipInt) {
        byte[] ipAddr = new byte[INADDRSZ];
        ipAddr[0] = (byte) ((ipInt >>> 24) & 0xFF);
        ipAddr[1] = (byte) ((ipInt >>> 16) & 0xFF);
        ipAddr[2] = (byte) ((ipInt >>> 8) & 0xFF);
        ipAddr[3] = (byte) (ipInt & 0xFF);
        return ipAddr;
    }

    /**
     * 把int->ip地址
     * @param ipInt
     * @return String
     */
    public static String intToIp(int ipInt) {
        return new StringBuilder().append(((ipInt >> 24) & 0xff)).append('.')
                .append((ipInt >> 16) & 0xff).append('.').append(
                        (ipInt >> 8) & 0xff).append('.').append((ipInt & 0xff))
                .toString();
    }

    /**
     * 把192.168.1.1/24 转化为int数组范围
     * @param ipAndMask
     * @return int[]
     * @throws FormatException
     */
    public static int[] getIPIntScope(String ipAndMask) throws FormatException {

        String[] ipArr = ipAndMask.split("/");
        if (ipArr.length != 2) {
            throw new FormatException("invalid ipAndMask with: "
                    + ipAndMask);
        }
        int netMask = Integer.valueOf(ipArr[1].trim());
        if (netMask < 0 || netMask > 31) {
            throw new FormatException("invalid ipAndMask with: "
                    + ipAndMask);
        }
        int ipInt = IPv4Util.ipToInt(ipArr[0]);
        int netIP =  ipInt & (0xFFFFFFFF << (32 - netMask));
        int hostScope = (0xFFFFFFFF << (32 - netMask));
        return new int[] { ipInt, netIP,hostScope  };

    }

    /**
     * 把192.168.1.1/24 转化为IP数组范围
     * @param ipAndMask
     * @return String[]
     */
    public static String[] getIPAddrScope(String ipAndMask) throws FormatException {
        int[] ipIntArr = IPv4Util.getIPIntScope(ipAndMask);
        return new String[] { IPv4Util.intToIp(ipIntArr[0]),
                IPv4Util.intToIp(ipIntArr[2]) };
    }

    /**
     * 根据IP 子网掩码（192.168.1.1 255.255.255.0）转化为IP段
     * @param ipAddr ipAddr
     * @param mask mask
     * @return int[]
     */
    public static int[] getIPIntScope(String ipAddr, String mask) throws FormatException {

        int ipInt;
        int netMaskInt = 0, ipcount = 0;
        try {
            ipInt = IPv4Util.ipToInt(ipAddr);
            if (null == mask || "".equals(mask)) {
                return new int[] { ipInt, ipInt };
            }
            netMaskInt = IPv4Util.ipToInt(mask);
            ipcount = MASK_SINGLE - netMaskInt;
            int netIP = ipInt & netMaskInt;
            int hostScope = netIP + ipcount;
            return new int[] { netIP, hostScope };
        }catch(FormatException e2){
            throw e2;
        }catch (Exception e) {
            throw new FormatException("invalid ip scope express  ip:"
                    + ipAddr + "  mask:" + mask);
        }

    }

}
